1. Field
An operation mechanism for a variety of electric apparatuses is provided.
2. Related Art
In a power window apparatus for a vehicle, for example, an operation mechanism which oscillatingly operates an operation grip provided inside a vehicle door to turn on a switch element provided below the operation grip has been widely used. Conventionally, a operation mechanism of this type (see Japanese Patent No. 2630315, for example) has an opening formed on a housing that covers a circuit board mounted with a switch element such that the switch element protrudes from the opening. An operation shaft of an operation grip is inserted into the opening to be engaged with actuators of the switch element, and in which the operation grip is axially and oscillatably supported by the housing near the opening.
The operation shaft protrudes downward from an operation portion of the operation grip, which is provided to cover and close the opening. When the operation portion is oscillatingly operated, the operation shaft is tilted below the opening and drives the actuators of the switch element. A predetermined electrical signal can be output from the switch element in accordance with a tilt direction of the operation shaft. The above configuration has a self-return mechanism in which the switch element causes the actuators to automatically return to an initial position through a return spring. If oscillating operational force applied to the operation portion of the operation grip is removed, the operation shaft in a tilted posture is pressed back to an original position due to resilience of the return spring.
In assembling the conventional operation mechanism configured as summarized above, the circuit board mounted with the switch element is positioned and installed in a pair of the upper housing and a lower housing. The operation shaft of the operation grip is inserted from above into the opening formed on the upper housing, and a leading end portion of the operation shaft is engaged with the actuators of the switch element. A rotation fulcrum of the operation grip is snap-joined to the upper housing. Thereby, the operation grip is axially supported by the housing.
In installing the operation grip to the housing in the operation mechanism of this type, when the operation shaft of the operation grip has been inserted into the opening of the housing by a predetermined length, the operation shaft needs to be accurately located at an engagement position with the actuators of the switch element (i.e., an electric component).
When the inserting operation of the operation shaft is started, the inside of the opening formed on the housing cannot be visually observed as being interrupted by the operation portion of the operation grip. A special positioning jig is required for accurately positioning the operation shaft with respect to the actuators. As a result, an assembler has to perform a complicated operation of installing the operation grip while using the positioning jig. Such operation also requires skill, and thus the installing operation of the operation grip forms a factor deteriorating the work efficiency of the assembly operation of the entire operation mechanism.
When a plurality of the operation grips are provided in a line, as in the case of the operation mechanism used in such apparatuses as the power window apparatus for a vehicle, the installing operation of the operation grip using the positioning jig needs to be performed more than once. Therefore, the work efficiency of the assembly operation is substantially deteriorated.